Reversible single wheel ratchet drive mechanism for conveyors



Mar 1964 P. SAMMARCO REVERSIBLE smcua: WHEEL RATCHET DRIVE MECHANISM FOR couvzyoss 3 Sheets-Sheet 1 Filed Dec. 12, 1960 INVENTOR ETER S 7HMARCO o- M ATTORNEY March 17, 1964 P. SAMMARCO 3,124,955-

REVERSIBLE SINGLE WHEEL RATCHET DRIVE MECHANISM FOR CONVEYORS 3 Sheets-Sheet 2 Filed Dec. 12, 1960 ATTORNEY March 17, 1964 P. SAMMARCO REVERSIBLE SINGLE WHEEL RATCHET DRIVE MECHANISM FOR CONVEYORS 3 Sheets-Sheet 3 Filed Dec. 12, 1960 Fig. 3

0W groamzv United States Patent 3,124,965 REVERSIBLE SINGLE WHEEL RATCHET DRIVE MECHANISM FOR CONVEYORS Peter Sammarco, Bellwood, Ill., assignor to International Harvester Company, Chicago, 111., a corporation of New Jersey Filed Dec. 12, 1960, Ser. No. 75,140 6 Claims. (Cl. 74-418) This invention relates to drives for manure spreaders, wagons, and they like, wherein a step-by-step motion is required to discharge, for example, loads from Wagons.

A general object of the invention is to provide a novel mechanism of the ratchet wheel type which comprises a single wheel and wherein the parts are so arranged that they may be conditioned to drive the ratchet wheel in either direction at the option of the operator.

A more specific object of the invention is to provide a novel driving mechanism which includes a single ratchet wheel having teeth of substantially sinusoidal shape and wherein there is provided a novel arrangement for tilting the driving pawl and the holding pawl so that the two operate conjunctively in either direction of operation.

A further object of the invention is to provide a novel control assembly, of simple design, which conditions the drive so that it operates in either direction.

These and other objects and advantages inherent in and encompassed in the invention will become more readily apparent from the specification and the drawings wherein:

FIGURE 1 is a side elevational view of the novel ratchet wheel drive mechanism showing the parts positioned in a counterclockwise driving arrangement;

FIGURE 2 is a sectional view taken substantially on the line 22 of FIGURE 3, illustrating the setting of the mechanism in a counterclockwise drive; and

FIGURE 3 is a sectional view of the novel ratchet drive mechanism taken substantially on the line 3-3 of FIG- URE 2.

Description of the Invention Describing the invention in detail and having particular reference to the drawings, there is shown a novel ratchet wheel drive generally designated 2 which comprises a ratchet wheel 3 keyed as at 4 to a drive shaft 5 which is shown mounted in a bearing 6 from a side wall or support structure 7 which may, for example, form the side of the wagon. The shaft 5 may drive a slatted chain type conveyor (not shown) such as operates over the wagon bed as well understood by those skilled in the art. The ratchet wheel has somewhat sinusoidal shaped peripheral teeth 9, each of which presents at its opposite sides driving surfaces 10 and 11 which are respectively engaged by the nodes or teeth 13 and 14 of the driving or the pushing pawl 15, said nodes 13 and 14 being respectively integrally formed on the oppositely extending diametrically arranged arms 91 and 17 of the pawl 15, the arms 91 and 17 projecting from the body portion 13 which is provided with a pivot opening 19 by means of which the pawl is pivoted on the pin 16, the pin 16 extending axially with respect to the ratchet wheel 3 adjacent to the periphery thereof and being supported, as best seen in FIGURE 3, on a pair of arms 22 and 23 which at their upper ends 24 and 25 are provided with bearings 26 and 27 which sleeve over the shaft 5, the inner and outer arms 22 and 23 flanking the ratchet wheel 3 therebetween and depending from the shaft 5 below the periphery of the wheel 3.

The lower ends of the arms 22 and 23 are interconnected by a bolt and spacer assembly 3!) which journals one end 31 of a pitman 32 which at its other end is journaled as at 33 on a crank throw 34 of a crank structure 35 which is suitably journaled on a shaft portion 36 from a bearing 37 supported from the support structure 7. The crank, of course, is operatively connected to a power source and is rotated to reciprocate the arm 32 which in turn causes the swing assembly constituted by the arms 22 and 23 to pendulate about the shaft 5.

In the position shown in FIGURE 1, it will be seen that the driving direction is counterclockwise as shown by the arrow and in FIGURE 2, the direction of rotation is clockwise. The reversing of the direction of rotation is accomplished by positioning the pawl 15 so that it enters the node 14 between the teeth 9 or the node 13 between said teeth. This positioning is accomplished through a shifting mechanism which comprises an arm portion 40 extending radially outwardly from the body portion 18 of the pawl 15, the outer end of the arm 40 being connected to a pin 41 which extends axially out- Wardly of the pawl through circumferentially elongated slots 42 in the outer hanger 23, the pin 4-1 being pivotally connected as at 43 to one end 44 of a link 45 which is continued at its opposite end into an operating handle 46. The link 45 is connected at a point spaced from its connection at 43 as at 47 to one end of a holding pawl control link 48 which at its other end is pivotally connected as at 49 to a radially extending arm 50 of a holding pawl generally designated 51. It will be understood that the pushing or driving pawl structurally is identical with that of the holding pawl 51. However, since their function is different, different numbers will be used to identify the parts. The pawl 51 comprises a body portion 52 which is pivoted on a pin 53 to the support structure 7. The holding pawl has radially extending arm portions 55 and 56 with nodes 57 and 58 which respectively are alternatively entered between the teeth 9 dependent upon the direction in which the ratchet wheel is rotating. As best seen in FIGURE 1, it will be seen that the node 57 is in position to enter between the teeth and prevent the wheel from oscillating back and forth, and in the position of FIGURE 2 the node 58 enters between the teeth 9. The driving pawl is maintained in its selected position by means of tension spring 60 which at one end is hooked around the pin 41 and at its other end to a pin 61 which is mounted on the arm 23 adjacent to its upper end and extends outwardly from its outer side, the rotation of the pin being such that it aligns with the pin 16 so that the axis of the spring 60 in the position of FIGURE 1 is to the right of the center line xx and in the position of FIGURE 2 to the left whereby biasing the pawl into the respective positions. Similarly the spring 63 of the holding pawl has one end pivoted on a pin 64 which is connected to the arm 23 adjacent to its pivot on the shaft 5 and its other end pivoted around the pin 49. It will be seen that the spring 63 swings between the two positions shown in FIGURE 1 and in FIGURE 2 so that in one position the axis of the spring 63 is below the center of the pin 53 and in the position of FIGURE 2 it is above and therefore its action is to hold the pawl in its selected position. It will be understood that the geometry of the control linkage 45, 48 is such that as the operating pawl is moved from one position to the other, the holding pawl moves into a complementary position.

A feature of the present invention is the provision of a speed selector for controlling the number of teeth into which the driving pawl enters and therefore controls the distance for each stroke of the driving mechanism that the ratchet wheel will move. This speed selector comprises a bracket suitably mounted by bolts 76 to the support plate 7 and having a series of openings or notches including an intermediately positioned notch 77 and two clockwise opening or notch positions 78 and 79 and two counterclockwise opening or notch positions 80 and 81. The bracket cooperates with a handle 82 which is provided with a pin 83 which extends from the inner side thereof and is adapted to be entered into any of the series of notches or openings at the option of the operator by merely deflecting the handle laterally as shown in dotted lines in FIGURE 3 and moving the handle circumferentially about the axis of the shaft 5 on which is pivotally mounted a plate 84 connected to the inner end of the handle 82. The plate 84 has mounted thereon at circumferentially spaced areas a holding pawl shield segment 85 and a driving pawl shieldsegrnent 86. These segments 85 and 86 are disposed outwardly of the periphery of the ratchet wheel'and overlap the same and extend axially inwardly and outwardly from the plate 84.

These segments are so positioned that in the event that the control mechanism is not properly set so that the holding pawl should accidentally not complement the position of the driving pawl the holding pawl shield 85 will be underposed with respect to either of the holding pawl nodes to prevent its entry into the ratchet wheel and therefore this will cause the ratchet wheel to rock or oscillate back and forth and prevent its being driven. Therefore, a novel safety feature is obtained in the arrangement.

It will be understood that the length of the pawl guard 86 is such that in the various positions of the control assembly generally designated 90, the respective driving pawl tooth 13 or 14 will slide over one or several teeth dependent upon the position that the guard is set so that the-respective pawl tooth slides over the shield or guard 86 and can enter only behind a selected number of teeth.

In the neutral position, of course, the shield prevents any of the nodes 13 or 14 from entering into the ratchet teeth, therefore the driving assembly pendulates freely while the nodes or teeth 13 and 14 slide over the shield 86.

Thus a novel and efficient ratchet wheel drive has been disclosed which incorporates only one wheel'and which provides a novel control assembly conjunctively positioning the driving pawl and the holding pawl into complementary positions and wherein the selecting mechanism affords novel holding pawl kickout means for positively preventing the holding pawl from being disposed in a position directly opposingthe action of the driving pawl.

What is claimed is:

1. In a two-way ratchet wheel drive, the combination of ratchetwheel means having teeth providing one set ofdriving surfaces for driving the wheel means in one direction and another set of driving surfaces for driving the wheel means in the opposite direction, pendulating drive means cooperable with the wheel means and including a driving pawl, a holiday pawl cooperable with the wheel means, and shift means operatively interconnecting said pawls simultaneously moving both of said pa-wls to engage with the corresponding set of surfaces and a speed control member having means for keeping said pawls out of a first position when the pawls are engaging, one set of surfaces and out of another position when the pawls are engaging another set of surfaces for reversing drive.

2. In a two-way ratchet wheel drive, the combination of ratchet wheel means having teeth providing one set of driving surfaces for driving the wheel means in one direction and another set of driving surfaces for driving the wheel means in the opposite direction, pendulating drive means coopera ble with thewheel means and including a driving pawl a holding pawl cooperable with the wheel means, and shiftmeans operatively interconnecting said pawls simultaneously moving both of said pawls to, engage with the corresponding set of surfaces, and speed control means comprising cam means interposed between the teeth and both of said pawls, and the cam means cooperable with the holding pawl disposed to hold the holding pawl out of engagement with theteeth under condition wherein said holding pawl is conditioned to engage the set of surfaces other than the set being engaged by the driving pawl.

3. In a twoway ratchet wheel drive, the combination of ratchet wheel means having two-way drive teeth, drive means for the wheel means including a driving pawl, a holding pawl cooperable with the wheel means, said pawls shiftable to first and second complementary positions for selectively driving the wheel means in first and second directions respectively, and drive-directioncontrol means having cams movable about the periphery of wheel means in response to setting of said control means in blocking position to at least one of said pawls being noncomplementally positioned to prevent disposition of the pawls in opposition to each other.

4. In a two-Way ratchet wheel drive, the combination of a ratchet wheel having two-way drive teeth, drive means for the wheel including a driving pawl, a holding pawl, said pawls complementally positionable in a first position engaging said teeth at one of the corresponding sides for driving the wheel in .a-first direction and in a second position engaging the opposite side of the teeth for driving the wheel in an opposite direction, and means intenpositionable between the teeth and at least one of the pawls for preventing engagement therebetween upon said palwls being noncomplementally positioned.

5. In a two-way ratchet wheel drive, the combination of a ratchet wheel having two-way drive teeth, drive means for the wheel including a driving-pawl, a holding pawl, said pawls complementally positionable in a first position engaging said teeth at one of the corresponding sides for driving the wheel in afi-rst direction and in a second position engaging the opposite side of the teeth for driving the wheel in an oppositedirect'ion, and said last mentioned means including :a baffle plate adjustable about the axis of the wheel and having cam portions engageable with respective pawls.

6. In a two-way ratchet wheel drive; the-combination of ratchet wheel means having :anaxis of rotation and having teeth providing one set of surfaces for driving the wheel means in one direction and another set of smfaces for drivingthe wheel means in the opposite direction; a pendulating ar-m pivoted on said axis; a driving pawl pivoted intermediate its ends to the pendulating.

arm and having a pair of diametrically spaced nodes alternately engageable, through pivotingof the driving pawl, with respective sets of surfaces; a holding pawl pivoted intermediate its ends adjacent to the wheel means and having a pair of diametrically extending nodesalternately engageable, through pivoting of the holdingpawl with respective surfaces; each pawl having a radial arm; interrelating linkage interconnecting said pawls and comprising a pair of pivotally interconnected "angularly disposed link elements pivotally interconnected at one of their ends and pivoted elsewhere to respective pawl radial arms,

spring means pivotally connected to said pendulating arm and to the radial arms of respective pawls and disposed with their vaxes past dead center position with respect to the pivots of respective pawls in each position thereof, said linkage settable in positions engaging the holding and driving paw-ls with respective surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A TWO-WAY RATCHET WHEEL DRIVE, THE COMBINATION OF RATCHET WHEEL MEANS HAVING TEETH PROVIDING ONE SET OF DRIVING SURFACES FOR DRIVING THE WHEEL MEANS IN ONE DIRECTION AND ANOTHER SET OF DRIVING SURFACES FOR DRIVING THE WHEEL MEANS IN THE OPPOSITE DIRECTION, PENDULATING DRIVE MEANS COOPERABLE WITH THE WHEEL MEANS AND INCLUDING A DRIVING PAWL, A HOLIDAY PAWL COOPERABLE WITH THE WHEEL MEANS, AND SHIFT MEANS OPERATIVELY INTERCONNECTING SAID PAWLS SIMULTANEOUSLY MOVING BOTH OF SAID PAWLS TO ENGAGE WITH THE CORRESPONDING SET OF SURFACES AND A SPEED CONTROL MEMBER HAVING MEANS FOR KEEPING SAID PAWLS OUT OF A FIRST POSITION WHEN THE PAWLS ARE ENGAGING ONE SET OF SURFACES AND OUT OF ANOTHER POSITION WHEN THE PAWLS ARE ENGAGING ANOTHER SET OF SURFACES FOR REVERSING DRIVE. 